Analysis and Testing of Container Cranes under Earthquake Loads

The increasing size of container cranes has resulted in vulnerability to seismic loads which has not previously been recognized. This paper presents the results of scale testing and analysis of a typical jumbo container crane subjected to earthquake loading. A series of 1/20^th scale shake table tests of the model structure is performed under increasing levels of acceleration to assess the response and identify potential failure modes. Numerous responses, including lateral displacement and uplift are monitored during the testing. Complimentary detailed nonlinear finite element time history analyses are also performed. It is found that the portal frame response dominates elastic behavior, which is captured well by analytical models. Stronger excitation produces uplift, which couples closely with elastic behavior. The resulting rocking, including its isolating nature, can be captured by analytical models.